Pumping device and method



wswm

March E3, E934@ H. W. PARKER PUMPING DEVICE AND METHOD Filed May 2l,1931 Patented Mar. 13, 1934 PATENT OFFCE PUMPING DEVICE AND METHODHoward W. Parker, Park Ridge, Ill., assigner to The E. H. Wachs Company,Chicago, Ill., a corporation of Illinois Application May 21, 1931,Serial No. 538,964

8 Claims.

The invention relates to pumping devices and to methods of pumping. Thepresent invention relates generally to devices of the type disclosed inmy copending application Serial No. 495,876 filed November 15, 1930, ofwhich the present invention isa continuation in part.

In general, the aim of the invention is to provide a pumping devicewhich is simple and sturdy in construction, which embodies very fewparts subject to operating wear or damage, is

. highly efcient in operation, and is capable of adaptation for manifolduses.

An object of the invention is to provide a Inovel pumping device inwhich a decreased pressure created by cavitation is utilized to producethe pumping action.

Another object is to provide a pump embodying a member mounted forrotation and having means thereon for creating decreased pressure bycavitaton, and means for utilizing the decreased pressure to produce aflow from a source .of iiuid to be pumped.

A further object of the invention is to provide a novel device forcreating a source of decreased pressure which includes means forproducing jets or streams of fluid moving flatw'se at or above a`critical speed whereby regions of decreased pressure are formed bycavitation.

More specically stated, an object of the invention resides in theprovision of a pumping device in which a member, rotatably disposed in afluid has means thereon for creating a plurality of jets or streams ofsuch fluid arranged -to discharge substantially radially of the memberand to travel laterally in the general direction of rotation of themember at the point of discharge, whereby each jet produces a followingregion of decreased pressure by cavitation; said member having meansassociated therewith for preserving the character of the streams untilthe effectiveness thereof is substantially dissipated, and means forestablishing communication between said regions of decreased pressureand a source of fluid to be pumped.

Another object of the invention is to provide a novel method of pumpingwhich embodies the production of a pumping pressure by cavitation.

A further object is to provide a novel method of pumping which includesthe steps of forming moving jets or streams of fluid within a main bodyof fluid to create regions of decreased pressure behind said streams,preserving the character of the streams until the working force (ci.23o-10s) thereof is dissipated, and establishing communication betweenthe said regions and a source of fluid to be pumped. f

Other objects and advantages will become apparent in the followingdescription and from the accompanying drawing, in which:

Figure 1 is a longitudinal axial section through a device embodying thefeatures of the invention.

Fig. 2 is a transverse section through the 65 device taken substantiallyalong the line 2-2 of Fig. 1.

Fig. 3 is a fragmentary and enlarged detail view showing the peripheralface of the rotating member.

Broadly, the present invention utilizes the principle of cavitation toproduce a decrease of pressure within a body of fluid, which pressuredecrease is employed as the pumping force. In the sense in which theterm is herein employed, cavitation may be defined as that formation ofa region of decreased pressure which is produced when an object moves atsuch a velocity or speed through a fluid that the pressure withing theregion, immediately behind the object, is so reduced below that amountof pressure which would preserve the natural ow of iuid to said region.In creating and using this force for pumping purposes, the presentinvention embodies a member journaled for rotation with a body of huid,which member has a plurality of nozzles thereon arranged to produce,when the member rotates, powerful jets or streams of fluid which aredischarged substantially radially of the member and which move laterallythrough the body of fluid. The velocity of lateral movement of thesejets is above the critical speed at which cavitation results so thateach stream is, in effect, the object which moves through the body offluid for producing a region of decreased pressure. Means are providedfor establishing communication between such regions and a source offiuid to be pumped.

The present structure further provides a plurality of members associatedwith the rotating member for interrupting the discharged jets, whichmembers are arranged to preserve the character of the stream until theworking force thereof is substantially expended and, in general, toincrease the ca'vitating eiciency of the jets. v

The substance in which the rotating member is immersed, as Well as thepumped substance, are herein characterized generally as fluids, but themost efcient operation of the pump occurs when there is a considerabledifference in the 110 comparative densities of the fluids. As a specicexample of one use, the pump may be employed to evacuate a container, inwhich case a satisfactory immersing fluid is water, while the fluid tobe pumped is air or another gas.

Referring more particularly to the drawing which illustrates merely fordescriptive purposes, a particular form of device embodying the featuresof the invention, l0 designates generally a casing section havingbearings 11 therein arranged rotatably to support a shaft 12. One end ofthe shaft 12 extends from the casing and carries a suitable member 13 bywhich the shaft may be connected with any well-known type of prime mover(not shown). The casing section 10 has a flat end wall 14 preferablyformed integrally therewith, through which wall the end of the shaft 12extends a short distance, a conventional type of packing gland 15 beinginterposed between the shaft and the end wall. The casing section 10has, adjacent the end wall 14, a radial flange 16 extending a shortdistance axially beyond the end wall to provide an annular shoulder 17which defines a circularlyshaped recess 18 facing outwardly from the endwall.

A second casing section 19 has a ange portion 20 thereon, fashionedsubstantially as the complement of the flange 16, and a centrally olfsetportion 2l which is disposed in opposition to the recess 18 when thesections are assembled. The recess 18 and the offset portion 2l thusprovide a closed compartment 22 within the casing. The flanges 16 and 20are provided with armular depressions 23 which, when the parts areassembled, define an annular bore 24. The bore 24 communicates with thecompartment 22 through a radially extending and outwardly flaringpassageway 25 provided between the face of the shoulder portion 17 ofthe flange 16 and the complementarily shaped, opposing face of a portion26 of the flange 20.

The end of the shaft 12, within the compartment 22, carries a member forrotation therewith, which member is herein shown as ccmprising a disk 27of such dimensions that it lits relatively snugly within the recess 18.The disk 27 carries means by which jets or streams of fluid aredischarged outwardly of the disk in the rotation thereof. One form ofsuch means is shown in Fig. 2 as comprising a plurality of lateralprojections or lugs 28 formed on or secured to the side face of the diskopposite the wall 14 and 'arranged in spaced annular series adjacent theperiphery of the disk. The rear or trailing face 29 of cach projection(with reference to the direction of rotation of the disk), and the frontor advancing face 30 are cut away to provide opposing faces on adjoiningprojections which dene nozzles 31. Preferably the nozzles taper from thecenter of the disk and are directed substantially radially thereof.

Adjacent the nozzle forming surfaces, the projections are fashioned toprovide enlarged pockets 32 opening toward the axis of the disk toentrap and deliver iluid to the nozzles. In forming the pockets, thefront face of the projections are preferably recessed arcuately, as at3.3, while the opposing rear faces slope sharply forwardly, as at 34,from the rear nozzle defining surfaces 29. The surfaces 33 and 34 on thesame lug meet to form a sharp knife-edge 35 facing forwardly in thedirection of rotation of the disk.

The disposition of the projections 2 8 with reference to the casingsections 10 and 19, is such that the peripheral faces of the lugs aredisposed substantially adjacent to the inner or restricted mouth of theflaring passageway 25 whereby, as the disk rotates, jets of fluiddischarged from each nozzle 31 flow through the passageway 25 into thebore 24.

While any suitable means may be utilized to insure rotation of the diskwith at least the peripheral portion thereof immersed in the fluid, ithas been found desirable constantly to cause a circulating flow of saidiluid through the device. For this purpose, the casing section 19 has aninlet passageway 36 (Fig. 2) communicating through the wall of theoffset portion 21 with the closed compartment 22. An inlet port 37 tothe passageway 36 is defined by a flange 38 to which a conduit (notshown), leading to a source of fresh fluid, may be secured. An outletpassageway 39 preferably located substantially oppositely of thepassageway 36 communicates with the bore 24 and has a flange 40 deningan outlet port 41. The flange 40 provides a connection with a conduit!"(not shown) for conveying discharged fluid from the device. Generally,discharge is to a suitable separating device (not shown) wherein anatural separation of fluids may take place at atmospheric pressure.

The operation of the parts, as they have thus far been described, is asfollows: A constant stream of fluid is delivered to the compartment 22through the passageway 36 where it cornes into contact with the exposedface of the rapidly rotating disk member 27. It is well recognized that,when a member rotates in a body of fluid, skin friction between the faceof the member and fluid produces a ow of the fluid in the direction ofrotation of the member at a velocity which is approximately equal toone-half the velocity of rotation of the member. Also, centrifugalaction causes any particle of water to travel outwardly from the axis ofrotation. The resultant of these forces causes the water flow toapproach the periphery of the disk at an acute angle.

The preferred formation of the projection faces 33 and .34, which dennethe pockets 32, is such that the inlet mouths of the pockets faceoppositely of the direction of flow of the water thereto. Moreover, theangular slope of the rear face 34 of each projection is determined byand corresponds with the angle at which the water flow approaches' theperiphery of the member. Theoretically, these angles should be exactlythe same so that any fluid not entrapped in one pocket may flow smoothlyalong the rear face of the next projection into a succeeding pocket.This formation avoids and eliminates the creation of regions ofdecreased pressure behind the projections by cavitation.

It will be evident that the iluid thus entrapped within the pockets willrotate at the same velocity as the pockets themselves, and will thenhave a certain additional centrifugal force outwardly of the rotatingmember. This force, at the wide base of each tapering nozzle 31, changesto static force which functions ,to deliver a powerful jet or stream offluid outwardly and substantially radially of the rotating member. Sincethese jets are constantly delivered duringthe rotation, the jets afterdischarge have a flat-wise lateral movement away from the rotatingmember, the general direction of which is tangential of the member atthe point of discharge. As a result, when the disk rotates ata properspeed, the lateral movement of each jet causes regions of decreasedpressure to form behind each jet.

The regions of decreased pressure produced by the cavitating effect ofthe jets are utilized to cause a flow of fluid to be pumped. In thepresent instance, this end is accomplished by providing an annular andradially extending passageway 42 (Fig. l) within the disk :27, whichpassageway extends from the hub portion approximately to the peripheryof the disk. Transverse reinforcing walls 43 provide adequate strengthin the unit. The disk has an annular wall 44 disposed concentrically ofthe shaft 12 to denne a port 45 located centrally of the disk andcommunicating with the passageway 42. The casing section 19 has an axialport 46 therein which is defined within the casing by an annular flange'47 arranged snugly to encircle the outer end of the annular wall 44 onthe disk. A tubular nipple 48, having screw-threaded engagement with thecasing section 19, communicates with the port 46 and, in turn, isarranged to receive a suitable conduit 49 by which communication with asource (not shown) of fluid to be pumped, such as a container to beevacuated, may be established.

The annular passageway 42 communicates with the region of decreasedpressure behind each jet. Thus, a short bore 50 (Figs. 1 and 3) in eachprojection leads from the passageway 42 to a port 51 located on theannular face of each projection 28 immediately behind the advancing edgeof said projection. As the disk rotates, therefore, the accumulativeeffect of all of the regions of decreased pressure is utilized .toproduce a flow of fluid to be pumped through the conduit 49, nipple 48,ports 46 and 45, passageway 42 and bores 50 to discharge through theports 51 into the regions of decreased pressure.

While the method of producing regions of decreased pressure by thecavitating effect of a plurality of powerful jets of the uid is, ofitself, operative, it has been found that, by providing means forpreserving the character of each jet substantially until the working orcavitation producing force thereof is expended, the eiliciency of thepump may be materially increased. The present invention embodies meansfor accomplishing this purpose in the nature of a plurality of elementsarranged successively to interrupt each jet and along which ltheinterrupted jets travel while cavitating. lThese elements, as shown inFig. 2, comprise relatively thin, flat blades 52 rigidly secured atspaced intervals throughout the passageway 25 between the compartment 22and bore 24.

The formation and dimension of each blade, as well as the dispositionthereof with respect to certain other parts associated therewith, isdenite. In considering the blades and the disposition thereof, only asingle blade .and its relationship to one or two jets need be discussed.Each blade is so disposed within the passageway 25 that one end thereofis closely adjacent to the peripheral face of the projections 28,whereby the blade interrupts each passing jet.

. The movement of any single particle of fluid as it is discharged froma nozzle is both outwardly and in the direction of rotation of the disk,the theoretical line along which said particle travels being theresultant of the forces producing said outward and lateral movements.

The blade extends generally along the line of this .resultant `with therear face .53 .of the blade located on the line of said resultant. Theinner end of the blade is preferably sharpened substantially to aknife-edge as may be seen at 54 to interrupt the jet cleanly.

If it is now presumed that the disk is rotating so that a jet has justbeen interrupted by a blade, the relationship of parts is indicated at A(Fig. 2). The jet, as the disk continues to rotate, will be dischargedtoward the rearside of the blade to form, together with the blade andthe adjacent portion of the projection, a triangularly-shaped region asshown at B. While, as has been stated, the direction of ejection of thejets is substantially radially,` it has `been found that the capacity ofthe pump is increased if the nozzles are formed to direct thev jets at aslight angle to the true radius of the disk and rearwardly therefromwith respect to the direction of rotation. It has been ascertained thatangles up to ten degrees produce satisfactory results. Thetriangularly-shaped region thus produced denes the region of .decreasedpressure produced by the-cavitating action of the jet, which regionincreases in size as the disk rotates. The location of the ports 51,immediately behind each nozzle 31, establis'hes communication with thetriangular region just after it has been formed, which communicationexists as long as the volume of said region increases.

The length of each blade will depend upon the density of thefluid-within the device as well as upon the speed of rotation of thedisk and the force of the jet. Theoretically, the length of the blade issuch that the contact between the jet and the blade is maintained aslong as -possible, which is until the working force of the jet or, inother words, the force which preserves the characteristic of the jet, isnearly expended. As a result, the triangular relationship of theelements will be maintained until the end of the jet which engages therear surface of the blade passes or breaks over the end of the blade.

The position of a nozzle when the jet therefrom breaks over the ends ofa blade determines the distance between the sharpened ends 54 ofadjacent blades. Thus, each jet, as shown at C (Fig. 2), successivelyencounters a blade substantially at the moment the jet breaks over theo-uter end of the preceding blade. This arrangement prevents the backpressure, which, of course, will be exerted in the region of decreasedpressure as soon as the jet breaks, from being exerted on the port 51and its associated passageways and conduits.

As each jet is interrupted by one blade, a succeeding nozzle approachesthe interrupting end of a preceding blade so that, immediately .afterany jet has been cut off and has broken over the end of a blade, asucceeding nozzle passes the blade to create a new triangular region.Obviously, this will cause the advancing face of the newly formed jet toforce any pumped fluid which was .drawn into the previous triangularregion outwardly from between the blades intothe bore 24, which may betermed a volute. Inasmuch as the outlet passageway 39 from the volutegenerally communicates with a conduit which leads to a suitable devicewherein natural separation of the fluids may occur, the back pressureexisting within the device is atmospheric pressure which is notsuflicient to break down or destroy the jets. Furthermore, the flow reoof uid Within the volute, which naturally occurs in a device of thischaracter, is directed away from the jets by the blades and by thenatural flow thereof.

As the device operates, successive operative steps may be observed.First, a fresh supply of fluid is delivered to a rapidly rotating disk,the action of which causes the fluid to flow outwardly of the disk. Asthe fluid approaches the periphery, it is entrapped in the pockets wherethe centrifugal force of the then rotating fluid is converted intostatic force for discharging a large number of relatively thin and verypowerful jets from the disk. These jets move laterally at or above acritical speed to produce regions of decreased pressure by cavitation.Each jet is successively interrupted by means which preserves thecharacteristics of the jet as long as the jet has a cavitation-producingforce, whereupon the jet simultaneously passes beyond its preservingmeans and is interrupted to allow it to disintegrate and discharge anypumped fluid. As each jet disintegrates, succeeding jets, formed andoperating in the same manner, effect a complete discharge of pumpedfluid into the volute, from which it is conducted out of the device.

It will be apparent from the foregoing that a novel pumping device, aswell as a novel method of' creating and utilising a pumping force, hasbeen provided. The device is sturdy in construction and embodies fewparts subject to Wear. Nor may the device be easily broken or disabledin use, inasmuch as only two relatively movable parts are employed.

I claim as my invention:

1. In a pumping device, the combination of a container, a rotatingmember in said container, means on said member for producing by thecentrifugal action of the rotating member jets of uid directedsubstantially radially of the member and moving bodily substantially ina straight line direction which is approximately tangential of themember at the point of discharge, means for driving said member at arotational velocity to produce such tangential body :movement of saidjet at the critical speed at which cavitation occurs, and means forsubjecting the source of fluid to be pumped to the decreased pressurecreated by cavitation.

2. In a pumping device, the combination of a container, a memberjournaled for rotation in said container, means on said member forproducing jets of fluid directed generally radially thereof, meansadjacent said member for interrupting the jets to form jet sections,said means together with a jet section and an adjacent part of saidmember being arranged to define a region of decreased pressure producedby the movement of said jet section, and passageways communicatingbetween the region and a source of iluid to be pumped.

3. In a device of the character described, the combination of acontainer for fluid, a member rotatably immersed in said uid, aplurality of jet producing nozzle devices on said member, means fordividing said jets into jet sections, means for establishingcommunication between a source of fluid to be pumped and the regionsimmediately behind the jet sections and means for ypreserving thecharacter oi the jet sections until the Working force thereof issubstantially expended.

4. A pumping device comprising, in combination, a container for fluid, amember rotatable in the container, means for driving said members,jet-producing devices on said member arranged to direct jets of fluidoutwardly therefrom, means adjacent said member and in the path of thejets for dividing the jets into sections and then preserving thecharacter of such sections, said means having such a relationship tosaid member and to the produced sections that the sections travellaterally along said means without deformation and are directed at anangle thereto whereby each section together with said means and a partof said member define a region the volume of which increases as thesection moves, and means for establishing communication between saidregions and a source of fluid to be pumped.

5. In a pumping device, the combination of a plurality of bladesarranged in spaced series, means for discharging a plurality of jets ofduid against said blades and at such an angle with respect thereto thatthe jets travel along said blades without deformation of the jets0ccurringand means for effecting relative movement between said bladesand said jets whereby each blade successively passes each jet, saidrelative moment being at a velocity above a crtical point at whichregions of decreased pressure are produced by cavitation.

6. The method of pumping which includes the steps of creating regions ofdecreased pressure by the cavitating elTect of moving jet-like bodies ofi'iuid, preserving the characteristics of said bodies during thecavitating action thereof, utilizing the regions of decreased pressureas a pumping force, and interrupting said bodies to permitdisintegration thereof and discharge of the pumped substance.

'7. The method of pumping which includes the steps of directing jets offluid angularly against relatively movable members whereby the jets aredivided into sections which have relative flatwise and unimpededmovement along the lengths of said members, effecting such relativemovement at a velocity whereby cavitation produces regions of decreasedpressure between said sections and members, and connecting said regionswith a source of iluid to be pumped.

8. In a pumping device, the combination of a container for fluid, amember journaled for rotation in said fluid, means on said member forproducing jets of fluid directed generally radially thereof, meansarranged in series adjacent said member and in the path of said jets fordividing said jets into sections, said means being disposed at an anglewhich substantially conforms to the direction of lateral motion of thesections whereby the inherent nature of the sections is maintained, andis angular with respect to the direction of discharge of the jets,whereby each section and a jet dividing means dene a region in whichpressure is decreased by cavitaton, and passageways leading to eachregion.

HOWARD W. y PARKER.

